Repair patches are utilized to repair of a variety of structures, such as vehicles including aircraft, water vehicles or the like, as well as buildings and other structures. In this regard, a repair patch may be comprised of a composite material, such as carbon fibers embedded in an epoxy matrix, with the composite repair patch being adhered to the structure in order to affect the repair.
Repair patches comprised of a composite material may be partially cured prior to the installation of the repair patches upon the structure. In this regard, a repair patch may be debulked and consolidated, such as in accordance with a double vacuum debulk (DVD) process, prior to its installation. As a result of the partial curing of the repair patch, however, porosity or delaminations may be disadvantageously introduced into the repair patch, which may adversely impact the performance and longevity of the repair patch following its installation. For example, porosity may be introduced as a result of the inclusion of an expired material, or as a result of a vacuum leak or an impropriety with respect to the cure temperature or another cure parameter.
Once the repair patch has been partial cured, the repair patch may be installed in order to repair the structure. In this regard, the repair patch may be adhered to the structure and then subjected to a final curing process once in place upon the structure. Following the installation of the repair patch, the repair patch may be inspected to determine, among other parameters, the porosity of the repair patch and the bond line defined by the adhesive between the repair patch and the structure. In an instance in which the repair patch and/or the bond line fails to satisfy the predefined requirements associated with the successful installation of a repair patch, such as in an instance in which the repair patch and/or the bond line has excessive porosity, the repair patch may be removed, the surface of the structure reworked and another repair patch installed. The process of removing an unsuccessful repair patch and reworking the surface of the structure prior to installing another repair patch may be a time consuming and expensive process that delays the eventual reentry of the structure into service.
By inspecting the repair patch following its installation, it is also difficult to discriminate between issues, such as excessive porosity, that are attributable to the repair patch or that are attributable to the bond line between the repair patch and the structure, or are attributable to geometric variations and surface coatings of the structure lying behind the repair patch. Moreover, with respect to the porosity of the repair patch, the inspection of the repair patch following the installation of the repair patch may prevents technician from determining whether the porosity was introduced during the partial curing of the repair patch prior to installation or during the final curing of the repair patch. Consequently, it may be difficult to determine with accuracy any systemic changes to the repair process that should be introduced.